Biological models

One of the main areas of basic research in homeopathy has been in in-vitro or in-vivo biological models of the action of ultra-molecular dilutions and their potential mechanisms of action, including the Similia principle (the concept of treating like with like).

Similia principle

The validity of the similia principle as a specific type of regulation is essential to characterise homeopathy as a regulation therapy. Evidence from experiments, both human and animal, demonstrates that all substances (including pesticides and carcinogens) which show an inhibitory effect at high concentrations, have a stimulatory effect at low concentrations. This phenomenon is called hormesis and occurs in all biological domains tested, with growing research support (Bellavite; Calabrese). In pharmacology, acute and chronic effects of drugs often have opposite action (paradoxical pharmacology: Bond), and many modern pharmaceutical agents display paradoxical secondary or rebound effects (Teixeira). Up to now, relatively few studies have been performed in this field. The most significant ones were conducted at the University of Utrecht, the Netherlands, which were able to show that self-recovery on the cellular level is stimulated by small doses of threatening conditions applied according to the similia principle (Van Wijk, Wiegant).

Meta-analyses

A critical review and meta-analysis focused on 135 experiments published in 105 articles exploring the protective effect of homeopathic dilutions against toxins (Linde). The studies were extremely diverse and included many different experimental models: 95 experiments were conducted in animals, 29 in plants, 7 in isolated organs and 4 in-vitro. The quality of most studies was poor, but more than 70% of the high quality studies reported positive effects. The report included a meta-analysis of 26 experiments involving experimental intoxication with arsenic and mercury: the mean protection due to high dilution treatments was about 20% (CI, 6.2–33.2).

A recent meta-analysis evaluated 67 in-vitro experiments in 75 publications of research on homeopathic dilutions. A majority of them reported high-potency effects. Positive findings were obtained in nearly three-quarters of all replicated studies. Even experiments with a high methodological standard could demonstrate an effect of high potencies. However, no positive result was stable enough to be reproduced by all investigators.

Repeated individual high potency studies

Over 100 biochemical, immunological, botanical, cell biological and zoological studies on high potencies, i.e. beyond a dilution of 10^-23 have been performed and subjected to laboratory-internal, multicentre or independent repetition trials.

Of these, 30 are initial studies. In the attempt to reproduce one of these initial studies, 53 follow-up studies yielded comparable effects, 8 studies showed a consistent, yet different result from the initial study, and 16 studies yielded no effects. When all repetitive studies are considered, 69% reported effects comparable to that of the initial study, 10% different effects, and 21% no effects. Independently performed repetition studies reported 44% comparable effects, 17% different effects, and 39% no effects.

24 experimental models in basic research on high homeopathic potencies have been repeatedly investigated. 22 models were reproduced with comparable results, 6 models with different results, and repetition showed no results for 15 models. Independent reproductions with either comparable or different results were found for seven models.

Basic research models to study the effects of high dilutions that have subsequently led to reproduction studies can be identified in the following areas: biochemistry, cultured cells, plants, isolated immune cells, isolated organs, and whole animals.

Repeated studies yielding comparable effects

Some of these experimental models were independently investigated by different researchers, with comparable results:

Biochemistry- Results on potentised ubiqinone were confirmed by the same working group.

- Results on potentised arsenic were confirmed by the same working group.

Betti L, Brizzi M, Nani D, Peruzzi M (1997). Effect of high dilutions of Arsenicum album on wheat seedlings from seed poisoned with the same substance. British Homeopathic Journal, 86: 86–89.

Brizzi M, Nani D, Peruzzi M, Betti L (2000). Statistical analysis of the effect of high dilutions of arsenic in a large dataset from a wheat germination model. British Homeopathic Journal, 89: 63–67. [PubMed]

Sainte-Laudy J, Belon P (2009). Inhibition of basophil activation by histamine: a sensitive and reproducible model for the study of the biological activity of high dilutions. Homeopathy, 98:186-97. [PubMed]

- Consistent multicentre results on potentised thyroxin and frog metamorphosis were obtained and subsequently confirmed by the same working group with potentised thyroxin and by others with potentised thyroidinum.

Carmine TC (1997). Effects of high potencies of tumour necrosis factor alpha on H202 production in cultured neuroblastoma cells by enhanced luminol-dependent chemiluminescence (ECL): a possible system for investigating the biological significance of homeopathic high potencies. British Homeopathic Journal, 86: 67–72.

Fisher P (1982). The treatment of experimental lead intoxication in rats by penicillinamine and plumbum met. Proceedings of the 35th congress of the Liga Medicorum Homeopathica Internationalis, Brighton, 320–332.

Fisher P, House I, Belon P, Turner P (1987). The influence of the homeopathic remedy Plumbum metallicum on the excretion kinetics of lead in rats. Human Toxicology, 6: 321–324. [PubMed]